@Avisheak 

Thanks for the information provided. It seems that the router loses internet connection every 30 minutes, but not reset itself automatically.

We can do some troubleshooting first.

1. When the WAN led shows red, please log into the web UI of the Archer A5 and show us a screenshot of the status page.

2. In the meantime, please connect your computer to the modem directly and test whether it works; if it works normally, you can connect it back to the Archer A5 by wired cable and clone the MAC address under advanced-network/internet page. 

3. Besides, please ensure that the firmware is up to date. 

Good day. 

@Kevin_Z 

Hey Tha ma Kevin for your guidance. I have done all the steps you mentioned however I am still facing the issue.

I have attached a SS of the staus page when I face the issue, the firmware is up to date too.

@Avisheak 

Hi,

firstly, it's very easy to figure out if your router is reset to the factory default settings or just losing internet connection. For example, if you have changed the login username/password, or WiFi SSID/password, etc. When problem happens, if the login username/password comes back to admin/admin, than it's reset. Otherwise, it may be some issue with the WAN connection.

BTW, if you haven't changed your default login username/password, anyone can login to your router and reset your router from the Web configuration page. This may be a monkey business from the neighbor kid. Who knows.

If you are confident that the router definitely keep reseting itselves, you don't need to waste time here, just apply for a replacement from the store/vendor on prerequisite that the warranty period.

@matthew.mfden 

Thanks Matthew for your reply.

Yea. I keep changing the user name and password for the router but whenever this happen, this goes back to its default user name and password (admin/admin).

I have purchased this thru service provider and now not sure how to replace this. 
With all these, does it look like it's the router hardware issue and I need to go for a new one?